Direct spray exhaust mixer system

Abstract

A mixer for a vehicle exhaust system includes an outer housing defining an exhaust gas flow path, wherein the outer housing includes an inlet opening and an outlet opening. A distribution pipe is configured to deliver a reduction fluid directly into the exhaust gas flow path. The distribution pipe has an inlet end associated with the inlet opening and an outlet end associated with the outlet opening. The distribution pipe comprises a fluid flow path that is coiled about a center of the exhaust gas flow path.

1 . A mixer for a vehicle exhaust system comprising:
 an outer housing defining an exhaust gas flow path, wherein the outer housing includes an inlet opening and an outlet opening; and   a distribution pipe configured to deliver a reduction fluid directly into the exhaust gas flow path, wherein the distribution pipe has an inlet end associated with the inlet opening and an outlet end associated with the outlet opening, and wherein the distribution pipe comprises a fluid flow path that is coiled about a center of the exhaust gas flow path.   
     
     
         2 . The mixer according to  claim 1  wherein the distribution pipe includes a plurality of orifices through which the reduction fluid is directly introduced into the exhaust gas flow path. 
     
     
         3 . The mixer according to  claim 1  wherein coils of the fluid flow path have an increasing radius about the center of the exhaust gas flow path. 
     
     
         4 . The mixer according to  claim 2  wherein a pump is provided upstream of an inlet tube, configured to pump a fluid through the distribution pipe and expel any other fluid or deposits out of the distribution pipe through the plurality of orifices. 
     
     
         5 . The mixer according to  claim 3  wherein one of the inlet and outlet ends of the distribution pipe extends from the inlet opening toward the center of the exhaust gas flow path to a radially innermost coil, and wherein the other of the inlet and outlet ends of the distribution pipe extends from a radially outermost coil to the outlet opening. 
     
     
         6 . The mixer according to  claim 1  including the inlet tube extending outward of the housing from the inlet opening and an outlet tube extending outward of the housing from the outlet opening, and wherein the inlet end of the distribution pipe is in fluid communication with the inlet tube and the outlet end of the distribution pipe is in fluid communication with the outlet tube. 
     
     
         7 . The mixer according to  claim 6  wherein the inlet tube and outlet tube are fluidly connected to one another via a multidirectional valve. 
     
     
         8 . The mixer according to  claim 7  wherein the reduction fluid delivered through the inlet and outlet tubes recirculates to a fluid supply. 
     
     
         9 . The mixer according to  claim 7  wherein the inlet and outlet tubes are fluidly connected to a fluid supply of the reduction fluid. 
     
     
         10 . The mixer according to  claim 8  wherein the fluid is cooled before returning to the fluid supply. 
     
     
         11 . A vehicle exhaust system comprising:
 an upstream exhaust component having a housing defining an exhaust gas flow path, wherein the housing includes an inlet opening and an outlet opening;   a downstream exhaust component that includes an exhaust aftertreatment component, wherein the upstream component is connected to the downstream component;   a distribution pipe positioned within the upstream exhaust component and configured to deliver a reduction fluid directly into the exhaust gas flow path, wherein the distribution pipe has an inlet end associated with the inlet opening and an outlet end associated with the outlet opening, and wherein the distribution pipe comprises a fluid flow path that is coiled about a center of the exhaust gas flow path; and   a pump is provided upstream of an inlet tube, configured to pump a fluid through the distribution pipe and expel any other fluid or deposits out of the distribution pipe through a plurality of orifices.   
     
     
         12 . The vehicle exhaust system according to  claim 11  wherein the inlet tube and an outlet tube are fluidly connected to a fluid supply of the reduction fluid. 
     
     
         13 . The vehicle exhaust system according to  claim 11  wherein the distribution pipe includes the plurality of orifices through which the reduction fluid is directly introduced into the exhaust gas flow path. 
     
     
         14 . The vehicle exhaust system according to  claim 13  wherein coils of the fluid flow path have an increasing radius about the center of the exhaust gas flow path, and wherein the coils are substantially circular. 
     
     
         15 . The vehicle exhaust system according to  claim 14  wherein one of the inlet and outlet ends of the distribution pipe extends from the inlet opening toward the center of the exhaust gas flow path to a radially innermost coil, and wherein the other of the inlet and outlet ends of the distribution pipe extends from a radially outermost coil to the outlet opening. 
     
     
         16 . The vehicle exhaust system according to  claim 15  including the inlet tube extending outward of the housing from the inlet opening and the outlet tube extending outward of the housing from the outlet opening, and wherein the inlet end of the distribution pipe is in fluid communication with the inlet tube and the outlet end of the distribution pipe is in fluid communication with the outlet tube. 
     
     
         17 . The vehicle exhaust system according to  claim 16  wherein the inlet and outlet tubes are fluidly connected to a fluid supply of the reduction fluid, and wherein the inlet tube and outlet tube are fluidly connected to a multidirectional valve configured to allow recirculation of fluid between the fluid supply and the distribution pipe. 
     
     
         18 . A method comprising:
 providing an outer housing that defines an exhaust gas flow path, wherein the outer housing includes an inlet opening and an outlet opening;   associating an inlet end and an inlet valve of a distribution pipe with the inlet opening;   providing a pump configured to the inlet end;   associating an outlet end and an outlet valve of a distribution pipe with the outlet opening, wherein the distribution pipe comprises a fluid flow path that is coiled about a center of the exhaust gas flow path; and   forming a plurality of orifices in the distribution pipe along the fluid flow path such that reduction fluid enters through the inlet end and is directly introduced into the exhaust gas flow path via the plurality of orifices with any remaining fluid exiting the outlet end;   closing the inlet valve to stop the fluid flow path of the reduction fluid;   opening the outlet valve;   activating the pump to push a fluid through the distribution pipe to remove reduction fluid and deposits potentially formed within the distribution pipe from the distribution pipe; and   opening the inlet valve to allow the fluid flow path of the reduction fluid to return.   
     
     
         19 . The method according to  claim 18  including extending one of the inlet and outlet ends of the distribution pipe from the inlet opening toward the center of the exhaust gas flow path and to a radially innermost coil, and extending the other of the inlet and outlet ends of the distribution pipe from a radially outermost coil to the outlet opening 
     
     
         20 . The method according to  claim 18  including extending an inlet tube outward of the outer housing from the inlet opening and extending an outlet tube outward of the outer housing from the outlet opening, and fluidly connecting the inlet and outlet tubes to a fluid supply of the reduction fluid. 
     
     
         21 . The mixer according to  claim 1 , wherein the outlet opening is in fluid communication with the multidirectional valve that is configured to control the delivery of the reduction fluid out of the outer housing.